1 files changed, 26 insertions, 2 deletions
diff --git a/source/blender/draw/engines/eevee/shaders/default_frag.glsl b/source/blender/draw/engines/eevee/shaders/default_frag.glsl
index fd1a10de548..c5dbf29a3f4 100644
--- a/source/blender/draw/engines/eevee/shaders/default_frag.glsl
+++ b/source/blender/draw/engines/eevee/shaders/default_frag.glsl
@@ -6,14 +6,38 @@ uniform float roughness;
 
 Closure nodetree_exec(void)
 {
+#ifdef HAIR_SHADER
+	vec3 B = normalize(cross(worldNormal, hairTangent));
+	float cos_theta;
+	if (hairThicknessRes == 1) {
+		vec4 rand = texelFetch(utilTex, ivec3(ivec2(gl_FragCoord.xy) % LUT_SIZE, 2.0), 0);
+		/* Random cosine normal distribution on the hair surface. */
+		cos_theta = rand.x * 2.0 - 1.0;
+	}
+	else {
+		/* Shade as a cylinder. */
+		cos_theta = hairThickTime / hairThickness;
+	}
+	float sin_theta = sqrt(max(0.0, 1.0f - cos_theta*cos_theta));;
+	vec3 N = normalize(worldNormal * sin_theta + B * cos_theta);
+	vec3 vN = mat3(ViewMatrix) * N;
+#else
+	vec3 N = normalize(gl_FrontFacing ? worldNormal : -worldNormal);
+	vec3 vN = normalize(gl_FrontFacing ? viewNormal : -viewNormal);
+#endif
+
 	vec3 dielectric = vec3(0.034) * specular * 2.0;
 	vec3 albedo = mix(basecol, vec3(0.0), metallic);
 	vec3 f0 = mix(dielectric, basecol, metallic);
-	vec3 N = (gl_FrontFacing) ? worldNormal : -worldNormal;
 	vec3 out_diff, out_spec, ssr_spec;
 	eevee_closure_default(N, albedo, f0, 1, roughness, 1.0, out_diff, out_spec, ssr_spec);
 
-	Closure result = Closure(out_spec + out_diff * albedo, 1.0, vec4(ssr_spec, roughness), normal_encode(normalize(viewNormal), viewCameraVec), 0);
+	Closure result = Closure(
+	        out_spec + out_diff * albedo,
+	        1.0,
+	        vec4(ssr_spec, roughness),
+	        normal_encode(vN, viewCameraVec),
+	        0);
 
 #ifdef LOOKDEV
 	gl_FragDepth = 0.0;